Display device



Feb. 18, 1936.

DI SPLAY DEVICE Filed May 31, 1935 IN VENT OR ATTORNEY A. KAUFMAN2,031,416

Patented Feb. 18,- 1936 PATENT OFFICE DISPLAY DEVICE Alfonse Kaufman,Long Beach, N. Y., assignor,

by mesne assignments, to Biolite, Inc., New

York, N. Y., a corporat ion of New York Application May 31, 1935, SerialNo. 24,242 5 Claims. (01. 40-130) This invention relates to displaydevices and more specifically to illuminated signs.

In general, it is an object of the invention to provide a device of thecharacter described, which will more emciently perform the purposes forwhich it is intended, which is simple and economical of construction,which can be expeditiously, conveniently and safely used, and which canbe readily manufactured and assembled.

Another object of the invention is to provide a translucent sign havingmoving gas and liquid elements therein; to provide such a sign whereinthe gas has an intermittent but regular motion within the liquid; and toprovide such a sign wherein the liquid is colored but wherein thecoloring does not become localized by the heat which generates the gas.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description, taken inconnection with the accompanying drawing, in which:

Fig. 1 is a front view in elevation of a device embodying one form ofthe invention; and Fig. 2 is an end view in elevation and partly insection of the device shown in Fig. 1.

This invention contemplates a display device mounted preferably in acasing and having an exposed translucent part inwhich a liquid may beseen to bubble. Heat is supplied to give the energy required to producethe bubbling and. light may be supplied to illuminate the liquid and thebubbles. The translucent part is in the form of a character such as aletter, a numeral, a sign, an emblem or a designer any combinationthereof. The term translucent is intended to embrace the termtransparent.

The liquid occupies but part of the space within the device, thepressure within the remainder of the space being at less thanatmospheric at room temperature. A volatile liquid such as acetone orether is preferably employed. This may have sufiicient natural color fordisplay purposes, or coloring matter may be added. The bubbling isattained by heating the lower end of the device, whereby, as describedbelow, a part of the liquid is gasified and passes through the remainderof the liquid to the top of the device when the normal room temperaturecauses the gas to condense and fall back as a liquid toward the bottomof the device.

The liquid in the device may be colored in any convenient way as byhaving a. dye in'solution as a constituent. Colored suspensions orpowders may be used. There is a tendency for the dye or other source ofcolor to bake out into that part of the device which is exposed to heatwith a result that, after a time, theliquid in the translucent part ofthe device returns to its normal condition which may be colorless. It iswithin the contemplation of the present invention to permit the liquidto remain in contact with the heated portion for a relatively shortperiod and to change constantly the liquid w ch is so in contact. Theliquid in the herein described device retains its color after long use,neither dye nor suspended coloring matter baking out on the walls of theheated reservoir.

In the form of the invention illustrated in Figs. 1 and 2, the upperportion of the device comprises a hollow glass display character it,which may represent a letter of the alphabet, or a display unit of anydesired shape. An upturned vapor chamber H is connected with theinterior of the character ill by means of a narrow capillary passagewayH. The diameter of the passageway is small as compared to the internaldiameter of the character 00. The former may be 1 mm. and the latter 6mm. Letters such as N or X have a vapor chamber at the lower end of eachleg. The vapor chamber II should be so proportioned that a bubble ofvapor remains in it in order to quickly start the operation of thedevice. A quantity of liquid is introduced which is slightly less thanthe interior volume of the character when the liquid is heated andexpanded during operation. The device is then evacuated and sealed oil.The particular liquid employed is determined by the available heat andthe degree of vacuum in the device and may contain a dye or otherornamental substances. Ether, acetone and such highly volatile fluidswill operate satisfactorily under conditions of low heat. A casing i3 isprovided and the character It] supported therein by a spring clamp Mwhich may be mounted to slide laterally and afiord adjustable spacingbetween the different characters. An electric lamp I5 is placed in thecasing l3 in close relation to the vapor chamber II and is arranged sothat light is directed upwardly against the character I!) while thelight source is concealed. The lamp l5 also provides the heat necessaryto cause operation of the device.

The operation is as follows:

The lamp I5 is lighted and communicates heat to the chamber II in whichmost of the liquid has settled. As chamber ll becomes warmer the volumeof contained vapor is expanded and the 55 rate of vaporizationincreased. The increasing pressure of the vapor forces all of the liquidout of the chamber II and into the passageway l2 and character [0. Asthe last of the liquid passes the lowest point of the passageway l2, abubble of vapor is released into the character it! where it rises to thetop surface of the liquid and condenses against the relatively coolupper surfaces which form a condensing chamber for the device. Thebubbles are released in spaced succession, the action being due to a.pressure difference between the two bodies of vapor, with periodicdischarges of vapor from the warm, higher pressure body to the cooler,low pressure body.

As illustrated in Fig. 2, the under surfac s of the chamber II andcapillary passage l2 are blackened. In an assembled sign the rate ofbubble discharge in the various characters may be equalized by varyingthe area of the blackened surfaces, and so varying the amount ofeffective heat applied.

The frequency of bubble discharge is increased by the capillary passage,and a much more effective display results than when the passage is ofthe same internal diameter as the character. Under identical temperatureconditions the device having a small capillary passage will release aconstant succession of bubbles whereas the device having the largerpassage will not operate. Identical temperature conditions may easily beprovided by applying a covering of moist paper to the upper portion ofthe device and allowing evaporation to produce a lower temperature atthat point than prevails at the lower vaporizing chamber, whereupon thedevice operates by atmospheric heat.

The particular size of the vapor chamber ii is not a critical factorprovided a bubble of vapor remains in it to serve as a nucleus when heatis applied since it is essential to quick operation that there be vaporat each end of the liquid column.

Many changes and modifications may be made in the device here shown anddisclosed without departing from the spirit and scope of the inventionas expressed in the following claims:

1. In a bubbling display device, a plurality of hollow translucentdisplay characters, a liquid contained in each of said characters, avapor chamber adjacent the lower end of each character and a passagewayjoining said chamber with the interior 01. said character, means foracter and a passageway joining said chamber with the interior of saidcharacter, means for generating a vapor pressure in said chamberswhereby a succession oi bubbles rises through said characters, and meansfor individually regulating the heat absorption of said vapor chamberswhereby the rate of bubble discharge in said characters may beequalized.

3. In a bubbling display device, a plurality of hollow translucentdisplay characters, a liquid contained in each of said characters, avapor chamber adjacent the lower end 01' each character and a passagewayjoining said chamber with the interior of said character, means forgenerating a vapor pressure in said chambers whereby a succession ofbubbles rises through said characters, and means including a removablecoating on each vapor chamber whereby the rate of bubble discharge insaid characters may be equalized.

4. In a bubbling display device, a hollow translucent display character,a liquid contained in said device, a vapor chamber extending upwardlyadjacent the lower end of said character, a. passageway of substantiallysmaller cross section than the interior of said character, saidpassageway extending between said vapor chamber and the interior of saidcharacter, and

means for generating vapor pressure in said character whereby asuccession of bubbles rises through the liquid in said character.

5. In a bubbling display device, a hollow translucent display character,a liquid contained in said device, a vapor chamber extending angularlyupward adjacent the lower end of said character,

a passageway of substantially smaller cross section than the interior ofsaid character, said passageway extending between the lower ends of saidcharacter and said vapor chamber, and means for generating vaporpressure in said character whereby a succession of bubbles rises throughthe liquid in said character.

ALFONSE KAUFMAN.

